Report: Groundwater contamination in southeast Wisconsin

Over the last 20 years, groundwater contamination has become a major issue in some parts of southeastern Wisconsin. And we’ve long been curious: Could it be coal ash?

Wisconsin is a coal-dependent state, and burning coal results in toxic coal ash, leftover coal waste that has concentrated levels of hazardous chemicals like arsenic, chromium, lead, mercury and molybdenum. Those hazardous chemicals can leach out of coal ash into the environment, especially when it gets wet, releasing dangerous pollution into our water supplies. In Wisconsin, large coal plants alone generate nearly 1.8 million tons of toxic coal ash annually, of which 85% goes to “beneficial use” projects. This includes dumping under churches and schools, under or atop roads, on park paths and more.

In our initial research, we found records accounting for more than 1 million tons of coal ash spread in these types of projects throughout Waukesha, Milwaukee, Racine, and Kenosha counties. It was time to look at the connection between the contamination and coal ash reuse.

Don’t Drink the Water report

Following a yearlong analysis, we found molybdenum levels beyond state enforcement levels in nearly half the wells tested in Southeastern Wisconsin; our research furthers shows that the closer the tested wells are to coal ash reuse sites, the higher the level of molybdenum contamination they tend to have.